They both admitted that they arranged for the transport and storage of the hazardous waste from Mississippi, and failed to tell both the trucking companies that hauled the waste and the personnel that unloaded it of the danger. Their storage facility was not properly permitted. Daryl Duncan created a company, Missouri Green Materials, for the purpose, Assistant U.S. Attorney Dianna Collins said in court. But the company was not registered as a permitted hazardous waste storage or recycling facility, she said.

The indictment says that as much as 300,600 pounds of the waste was trucked to the warehouse from Oct. 30, 2013, to Dec. 3, 2013.

The materials were stored in a warehouse in a flood plain for more than four years. The building, at 7627 Zero Road, is near the small town of Berger, southeast of Hermann. It is across the road from Little Berger Creek, which empties into the Missouri River less than a mile away.

The material, spent bead blast waste, contains heavy metals such as cadmium, chromium and lead, court documents say. It was generated when paint was stripped from tanks, planes and other military equipment. It was stored in 55-gallon drums and “Super Sack” containers about 4 feet square, prosecutors said.

The Duncans have agreed to pay $1.5 million to the U.S. Environmental Protection Agency for the costs of dealing with the waste. They could face probation or a sentence of six months behind bars for the crime under federal sentencing guidelines.

The waste was dumped in Mississippi but was dug up years later and transported to Missouri after an Ohio company, U.S. Technology Corp. of Canton, was repeatedly ordered by regulators to remove it, prosecutors have said.

If 75 percent of the waste had been recycled within a year, it would not have been considered hazardous.

In a September 2016 consent agreement between the U.S. Environmental Protection Agency and U.S. Technology, the company agreed to form a plan to properly remove the waste from Missouri Green Material’s facility and test for any soil contamination. But prosecutors said the company did not.

U.S. Technology and president Raymond Williams, 71, both pleaded not guilty in the case. A hearing has been scheduled to change both pleas on June 19.

Both companies were indicted April 26 in St. Louis on a felony count of conspiracy. The Duncans and Williams were indicted on a conspiracy charge and a charge of transportation of hazardous waste.